Fuel systems which supply fuel to a combustion chamber in a gas turbine engine are well known in the art. Generally, a plurality of circumferentially distributed fuel nozzles forming an nozzle array in the combustion chamber, are used to ensure sufficient distribution of the fuel. The fuel nozzle array typically comprises a plurality of fuel nozzle tip assemblies for atomizing fuel into the combustion chamber. The nozzle tips are connected to a fuel manifold which is in fluid communication with a fuel source.
One conventional construction of a fuel manifold employs a machined ring having an annular channel sealed with a plate to form a circumferential fuel distribution passage. An alternative fuel manifold construction involves use of bent tubes rather than machined rings. Nevertheless, the tubes are typically very susceptible to dynamic excitation due to their lack of stiffness and therefore the number of mounting locations of the tubes has to be significantly increased. The tubes are also more difficult to insulate as tube over tubes configurations are difficult to manufacture and assemble. Furthermore, the tubes cannot be readily adaptable to and packaged with, for example, heating devices or heat pipes. In addition, fuel manifolds work under high temperature conditions and there is no tolerance for the risk of fuel leakage. Thus, a conservative design of seals for the fuel manifolds (either machined rings or tubes) is desirable.
Accordingly, there is a need to provide an improved fuel manifold for gas turbine engines.